Daryl took the marker from Hill. He considered mismarking things just to get himself removed from the detail, but this wasn't a game. He had a chance here to make a difference, to help stop the terrorist, and save innocent lives. He'd seen enough death and destruction back home, and he wanted to do his part to prevent more death and destruction.
He sighed, and set to work, ignoring Hill and Dumbledore both. Oh, he kept half an ear on them, at least until Dumbledore popped out of the room, but the majority of his focus was on the towels and the task in front of him.
He took a moment to deliberately sniff each of the specimens in turn, going back over them a second time before marking those he determined to be the same. Recapping the marker, he held it out to Hill to signify the conclusion of his analysis.